Prolongation in expiration evoked from the ventrolateral pons of
the adult rat.
Jodkowski, Jozef S., Sharon K. Coles, and Thomas E. Dick.
Departments of Medicine, Neuroscience, and Physiology and
Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
-5000
APStracts 3:0481A, 1996.
Activation of neurons in the ventrolateral (vl) pons was hypothesized
to alter the breathing pattern since previous studies demonstrated
apneusis after inhibiting neuronal activity with bilateral muscimol
(10 mM) microinjections into the vl pons (17). The excitatory amino
acid, L-glutamate (10 mM) was microinjected (10-100 nl) into the vl
pons in anesthetized, vagotomized, paralyzed, and ventilated adult
rats (n=8). In four of these animals, the target site was approached
from the ventral surface of the pons to avoid penetrating the
dorsolateral (dl) pons. The expiratory phase was prolonged
transiently and concurrently with the microinjection. The location of
the injection sites included the A5 area, was independent of the
approach, and was distinct from the dl pons. These results complement
our previous data and indicate that neurons located in vl pons
influence respiration, specifically, by prolonging expiration when
activated and by delaying the inspiratory to expiratory phase
transition when inhibited.
Received 2 July 1996; accepted in final form 15 October 1996.
APS Manuscript Number A697-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996